1972 240Z Steering Rack Bump Stops in Suspension and Steering Posted January 8, 2017 · Report reply I was just messing with one of these today. On mine I 'unscrewed' them. They are just a steel ring with a rubber lining, covering a zerk port. I tried tapping them off first, but when I tried to turn them, they were about half way onto the threads, so they just screwed off. I figured that was easier on the rubber than dragging them across the threads. I screwed them back on.Somebody who knows more than me can probably tell us if they are stops, or just covers for the zerk opening, or both.